✨ Add errors.Errorf

errorf.go

@@ -0,0 +1,61 @@
+package errors
+
+import "fmt"
+
+// Returns a ResponsableError formatted from the message, with the specified status.
+// Errorf passes the heavy lifting off to fmt.Errorf, and returns a similar error.
+// If one error is passed in the format, this will return an UnwrappableError.
+// If more than one error is passed in the format, this will return an UnwrappableErrors.
+func Errorf(status int, format string, parts ...any) ResponsableError {
+	err := fmt.Errorf(format, parts...)
+	msg := err.Error()
+	er := &erf{status, msg}
+	if we, ok := err.(wrappedError); ok {
+		return &wrapErr{er, we.Unwrap()}
+	}
+	if wes, ok := err.(wrappedErrors); ok {
+		return &wrapErrs{er, wes.Unwrap()}
+	}
+	return er
+}
+
+var _ ResponsableError = new(erf)
+
+type erf struct {
+	stat int
+	msg  string
+}
+
+func (e *erf) Status() int {
+	return e.stat
+}
+
+func (e *erf) Error() string {
+	return e.msg
+}
+
+func (e *erf) Msg() string {
+	return e.msg
+}
+
+var _ UnwrappableError = new(wrapErr)
+
+type wrapErr struct {
+	*erf
+	err error
+}
+
+func (e *wrapErr) Unwrap() error {
+	return e.err
+}
+
+var _ UnwrappableErrors = new(wrapErrs)
+
+type wrapErrs struct {
+	*erf
+	errs []error
+}
+
+func (e *wrapErrs) Unwrap() []error {
+	return e.errs
+}

errorf_test.go

@@ -0,0 +1,71 @@
+package errors
+
+import (
+	"errors"
+	"net/http"
+	"testing"
+
+	"github.com/stretchr/testify/suite"
+)
+
+func TestErrorf(t *testing.T) {
+	suite.Run(t, new(ErrorfTestSuite))
+}
+
+type ErrorfTestSuite struct {
+	suite.Suite
+}
+
+func (s *ErrorfTestSuite) TestNoWrap() {
+	var err ResponsableError = Errorf(http.StatusTeapot, "%d is more than %d", 42, 13)
+	s.Assert().NotNil(err)
+
+	_, ok := err.(UnwrappableError)
+	s.Assert().False(ok)
+
+	_, ok = err.(UnwrappableErrors)
+	s.Assert().False(ok)
+
+	exp := "42 is more than 13"
+	s.Assert().Equal(exp, err.Error())
+	s.Assert().Equal(exp, err.Msg())
+	s.Assert().Equal(http.StatusTeapot, err.Status())
+}
+
+func (s *ErrorfTestSuite) TestWrapOne() {
+	var wrapped error = errors.New("Here is my handle.")
+	var err ResponsableError = Errorf(http.StatusTeapot, "I'm a little teapot. %w", wrapped)
+	s.Assert().NotNil(err)
+
+	we, ok := err.(UnwrappableError)
+	s.Assert().True(ok)
+
+	_, ok = err.(UnwrappableErrors)
+	s.Assert().False(ok)
+
+	exp := "I'm a little teapot. Here is my handle."
+	s.Assert().Equal(exp, we.Error())
+	s.Assert().Equal(exp, we.Msg())
+	s.Assert().Same(wrapped, we.Unwrap())
+}
+
+func (s *ErrorfTestSuite) TestWrapTwo() {
+	var wrappedOne error = errors.New("short and stout")
+	var wrappedTwo error = errors.New("Here is my handle.")
+	var err ResponsableError = Errorf(http.StatusTeapot, "I'm a little teapot: %w. %w", wrappedOne, wrappedTwo)
+	s.Assert().NotNil(err)
+
+	_, ok := err.(UnwrappableError)
+	s.Assert().False(ok)
+
+	we, ok := err.(UnwrappableErrors)
+	s.Assert().True(ok)
+
+	exp := "I'm a little teapot: short and stout. Here is my handle."
+	s.Assert().Equal(exp, we.Error())
+	s.Assert().Equal(exp, we.Msg())
+	unwrapped := we.Unwrap()
+	s.Assert().Len(unwrapped, 2)
+	s.Assert().Same(wrappedOne, unwrapped[0])
+	s.Assert().Same(wrappedTwo, unwrapped[1])
+}

go.mod

@@ -1,3 +1,11 @@
 module codeberg.org/danjones000/responsable-errors
 
 go 1.21.5
+
+require github.com/stretchr/testify v1.8.4
+
+require (
+	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
+)

go.sum

@@ -0,0 +1,10 @@
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/stretchr/testify v1.8.4 h1:CcVxjf3Q8PM0mHUKJCdn+eZZtm5yQwehR5yeSVQQcUk=
+github.com/stretchr/testify v1.8.4/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXlSw2iwfAo=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

interface.go

@@ -27,3 +27,13 @@ type UnwrappableErrors interface {
 	ResponsableError
 	Unwrap() []error
 }
+
+type wrappedError interface {
+	Error() string
+	Unwrap() error
+}
+
+type wrappedErrors interface {
+	Error() string
+	Unwrap() []error
+}